[SGD] TrainerV2 API interface (#17447)
[SGD] TrainerV2 API interface (#17447)

Co-authored-by: Amog Kamsetty <bb6cdf742ece99f78d3d69aad127491bb98d7489@yahoo.com>
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray